Retirement Plans, Components of Net Periodic Benefit Cost for the Pension and Postretirement Tables (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Pension Plan [Member]
Net period benefit cost for the pension and postretirement plans
Defined Benefit Plan, Service Cost	$ 508	$ 800	$ 2,263	$ 2,392
Defined Benefit Plan, Interest Cost	2,943	2,794	8,380	8,165
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(8,649)	(8,243)	(25,949)	(24,647)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(54)	(63)	(161)	(188)
Defined Benefit Plan, Amortization of Gain (Loss)	0	0	0	37
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Total	(5,252)	(4,713)	(15,467)	(14,241)
Other Postretirement Benefits Plan [Member]
Net period benefit cost for the pension and postretirement plans
Defined Benefit Plan, Interest Cost	18	20	54	59
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(19)	(19)	(56)	(56)
Defined Benefit Plan, Amortization of Gain (Loss)	(7)	(7)	(21)	(22)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Total	$ (8)	$ (6)	$ (23)	$ (19)